Bonding properties and isomeric conversion pathways of singlet BeSi4 clusters

► BeSi4 isomers were DFT-optimized. ► Hirshfeld charges, Mayer bond orders, and Mayer total valences are analyzed. ► Potential energy curves of reactants entrance channels were calculated. ► Transition states of isomeric conversions were confirmed. ► Conversion progress is discussed by energies, structures, and Mayer bond orders.